repudiate vs refuse

repudiate is not a noun while refuse is a noun.

Word	Noun	Adjective	Verb	Adverb
repudiate	No	No	Yes	No
refuse	Yes	No	Yes	No

As verbs, refuse is a hypernym of repudiate; that is, refuse is a word with a broader meaning than repudiate:

Other hypernyms of repudiate include decline.

repudiate (noun)	refuse (noun)
	food that is discarded (as from a kitchen)

repudiate (verb)	refuse (verb)
refuse to acknowledge, ratify, or recognize as valid	show unwillingness towards
cast off	not accept as true
reject as untrue, unfounded, or unjust	refuse to let have
refuse to recognize or pay	refuse entrance or membership
	elude, especially in a baffling way
	resist immunologically the introduction of some foreign tissue or organ